High Resolution Records of Benthic foraminifers in the Late Neogene of the Northeastern Atlantic

Schnitker, Detmar

doi:10.2973/dsdp.proc.81.117.1984

Cited by 14 publications

(9 citation statements)

References 26 publications

(35 reference statements)

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“…Another faunal change occurring in the middle Miocene has also been recognized in the North Atlantic (Schnitker, 1984;Miller and Katz, 1987;Thomas, 1986bThomas, , 1986c. These changes have been related to either a decrease in temperature as documented by changes in oxygen isotope values (Schnitker, 1984;Douglas and Woodruff, 1981;Woodruff, 1985) or to increased primary productivity (Miller and Katz, 1987).…”

Section: Site 736mentioning

confidence: 78%

Middle Eocene to Holocene Benthic Foraminifer Assemblages from the Kerguelen Plateau (Southern Indian Ocean)

Schröder-Adams¹

1991

Proceedings of the Ocean Drilling Program

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Middle Eocene to Holocene benthic foraminifers were studied in sediments from Sites 736, 738, and 744 (Kerguelen Plateau). Significant faunal changes took place in the middle Eocene, late Eocene/early Oligocene, middle Miocene, and late Miocene. The benthic assemblages are characterized by gradual species replacements. Assemblage boundaries are defined where first appearance datums (FAD's) and last appearance datums (LAD's) concentrate. The Eocene fauna was dominated by Nuttallides truempyi. Buliminids became important at the end of the Eocene and in the early Oligocene Nuttallides umbonifera became dominant. The FAD of N. umbonifera is coeval with the onset of the first paleoceanographic indications, such as ice rafted material, of Antarctic glaciation. The establishment of the Antarctic Circumpolar Current in the middle Oligocene is reflected at Site 738 by an erosional hiatus. The increase in relative abundance of Nuttallides umbonifera at Site 744 during the same interval indicates cold, carbonate-corrosive bottom water. Epistominella exigua dominates the bathyal to abyssal upper Miocene to Holocene sediments at Sites 744 and 738, preferring the high supply of organic matter associated with increased upwelling near the Antarctic convergence. Site 736 has a benthic fauna, highly diluted by biosiliceous sedimentation. Significant increases of benthic foraminiferal numbers may indicate changes of the Polar Front during Pliocene/Pleistocene time.

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Section: Site 736mentioning

confidence: 78%

Middle Eocene to Holocene Benthic Foraminifer Assemblages from the Kerguelen Plateau (Southern Indian Ocean)

Schröder-Adams¹

1991

Proceedings of the Ocean Drilling Program

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“…The total relative abundance of buliminid, cassidulinid and Pullenia species (Figure 6a) decreased during deglaciation in core 5K. High relative abundances of these species have been linked to the occurrence of waters with a relatively low oxygen content (Schnitker, 1984;Kaiho, 1994). This faunal pattem might thus be seen as evidence that waters at 5K were less ventilated during glacial isotope stage 2 and interglacial stage 3.…”

Section: The Relative and Absolute Abundance Data For The Most Commonmentioning

confidence: 96%

Northeastern Atlantic benthic foraminifera during the last 45,000 years: Changes in productivity seen from the bottom up

Thomas¹,

Booth²,

Maslin³

et al. 1995

Paleoceanography

212

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Abstract. We studied benthic foraminifera from the last 45 kyr in the >63 tam size fraction in Biogeochemical Ocean Flux Studies (BOFS) cores 5K (50ø41.3'N, 21ø51.9•V, depth 3547 m) and 14K (58ø37.2'N, 19ø26.2%V, depth 1756 m), at a time resolution of several hundreds to a thousand years. The deepest site showed the largest fluctuations in faunal composition, species richness, and benthie foraminiferal accumulation rates; the fluctuations resulted from changes in abundance of Epistorninella exigua and Alabaminella weddellensis. In the present oceans, these species bloom opporttmistically when a spring plankton bloom results in seasonal deposition of phytodetritus on the seafloor. The "phytodetritus species" had very low relative abundances and accumulation rates during the last glacial maximum. A strong increase in absolute and relative abundance of E. exigua and A weddellensis during deglaciation paralleled the decrease in abundance of the polar planktonic foraminifer Neogloboquadrina pachyderma (s), and the increase in abtmdance of warmer water planktonic species such as Globigerina bulloides. This strong increase in relative abundance of the "phytodetritus species" and the coeval increase in benthie forammiferal accumulation rate were thus probably caused by an increase in the deposition of phytodetritus to the seafloor (and thus probably of surface productivity) when the polar front retreated to higher latitudes. The abundance of "ph3rtodetritus species" decreased during the Younger Dryas, but not to the low levels of fully glacial conditions. During Heinrich events (periods of excessive melt-water formation and ice rafting) benthie accumulation rates were very low, as were the absolute and relative abundances of the "phytodetritus species", supporting suggestions that surface productivity was very low during these events. In both cores Pullenia and Cassidulina species were common during isotope stages 2, 3 and 4, as were bolivinid, buliminid and uvigerinid species. High relative abtmdances of these •ies have been interpreted as indicative either of sluggish deep water circulation or of high organic carbon fluxes to the seafloor. In our cores, relative abundances of these species are negatively correlated with benthic foramini feral accumulation rates, and we can thus not interpret them as indicative of increased productivity during glacials. The percentage of these "low oxygen" species calculated on a "phytodetritus species" -free basis decreased slightly at deglaciation at 5K, but not at 14K. This suggests that decreased production of North Atlantic Deep Water during the last glacial might have slightly affected benthic foraminiferal faunas in the eastern North Atlantic at 3547 m depth, but not at 1756 m. In conclusion, major changes in deep-sea benthie foraminiferal faunas over the last 45,000 years in our cores from the northeastern Atlantic were the result of changes in surface water productivity, not of changes in deep water circulation; productivity was lower during the glacial, probably because of ex...

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“…Cassidulina teretis was first described by Tappan (1951) and documented from the mid-Miocene to present in Arctic/subarctic shallow-water deposits and deep-sea environments (e.g., Feyling-Hanssen, 1980, 1985FeylingHanssen et al, 1983;Schnitker, 1984;Murray, 1987;Jansen et al, 1990;Polyak et al, 2002Polyak et al, , 2013. Seidenkrantz (1995) investigated morphological variability of this species using the SEM in tests from Pleistocene deposits in the North Atlantic region (Fig.…”

Section: Introductionmentioning

confidence: 98%

RE-EXAMINATION OF THE USE OFCASSIDULINA NEOTERETISAS A PLEISTOCENE BIOSTRATIGRAPHIC MARKER IN THE ARCTIC OCEAN

Lazar

Polyak

Dipre

2016

Journal of Foraminiferal Research

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High Resolution Records of Benthic foraminifers in the Late Neogene of the Northeastern Atlantic

Cited by 14 publications

References 26 publications

Middle Eocene to Holocene Benthic Foraminifer Assemblages from the Kerguelen Plateau (Southern Indian Ocean)

Middle Eocene to Holocene Benthic Foraminifer Assemblages from the Kerguelen Plateau (Southern Indian Ocean)

Northeastern Atlantic benthic foraminifera during the last 45,000 years: Changes in productivity seen from the bottom up

RE-EXAMINATION OF THE USE OFCASSIDULINA NEOTERETISAS A PLEISTOCENE BIOSTRATIGRAPHIC MARKER IN THE ARCTIC OCEAN

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